Method and apparatus for forming tubes



Jan. 14, 1930. P. A. FAVR 1,743,950

METHOD 'AND APPARATUS FOR FORMING TUBES Filed Nov. 3, 1928 6 Shees-Shee't l Jan. 14, 1930. P. A. FAVRE i METHOD AND APPARATUS FOR FOMING TUBES 6 Sheets-Sheet l I l i l ,tf fier/@ Artzrneyg Jan. 14, 1930. P, A, FAVRE 1,743,960

METHOD AND APPARATUS FOR FORMING TUBES Filed Nov. 3, 1 928 6 Sheets-Sheet 5 Jam 14, 1930. P. A` FAVRE 1,74%950 METHOD AND APPARATUS FOR FORMING TUBES Filed Nov. 3, 1928 6 Sheets-Sheet 4 Jam M3@ 1930m P. A. FAVRE 1,743,960

METHOD AND APPARATUSy FOR FORMING TUBES Filed Nov. 5, 1928 6 Sheets-Sheet 5 ZYQUZ;

Jan. 14, 1930.' v v P. A. FAVRE Y 1,743,960

{ METHOD AND APPARATUS FOR FORMING TUBES Filed Nov. 5, 1928 e sheets-sheet 6 Patented Jan. 14, 1930 UNITED STATES PATENTl OFFICE PIERRE ANDRE/ravin, or cnosNE, FRANCE UMETI-ID .AND 4APPARATUS FOR FQRMING l Application led November 3, 1928, Serial No. 317,081, and in Belgium November 17, 1927.

The present invention relates to improve.-

ments in methods and apparatus for drawin fusible material into the form of tubes anV Vmore especially, to methods land apparatus 5 for transforming blocks of glass into tubular form. l f

Glass tubing is', at present, manufactured `almost entirely in glass making centers having an abundance of lire-clay, silica and simi- 10 lar raw materials for the manufacture of glass and for the maintenance of furnaces. Countries lacking the necessary furnace and glass making materials have hitherto been forced to import the latter or buy finished tubing. In the one case there has been heavy charges for freight, in the other, -equally heavy charges for breakage.

But even in the Icenters best equipped toA turnout tubing, the methods in useleave tice to melt a charge of glass in a furnace and then, if possible, convert the charge entirely into tubing. If orders are slack, no charge is melted since the furnaces and the tube making machines are, so to speak, interdependent. v

Finally, no single machine has as yet been available for permitting changes in the di- /ameter of the tube and of the nature of the glass during the drawing operation.

One of the objects lof the invention-is to provide a met od for making tubing permitf ting the economical manufacture of the latter in placeslacking both in glass and furnace making materials.

Another object is to provide a method for rendering the furnace operation independent of the drawing operation, thus permitting one to be continued while the other is inoperative. I

A` furtherobject is to replace the prior art methods of forming tubing in which a rotating mandrel or forming-element is used by a method permitting the same result to be obtained with a non-rotating mandrel or forming element.

An additional object is to provide means for varying the diameter of the tubing being drawn in the course of the drawing operation and without interrupting the latter.

much to be desired. Thus, it is common pracyin Fig. 4;

A still further object is to provide means for drawing glass tubing of varying'co'mposition or co or in the same machinevwlth- `out 'interruption in passing from one type of glass to another.

Still another object is to provide means for sectioning ,a predetermined length ,of drawn tubing. While thelatter is moving through the drawing machine.

. 'Other objects will appear# in the course of the detailed description now to be given with reerlence to the accompanying drawings in w 1c Fig. 1 represents a block of glass adapted for use in the improved method and apparatus; Aj

Fig. 2 illustrates the assembly of a guide mandrel and die constructed in accordance with the invention; v

Fig. 2l is a section through a preferred form of die;

Fig. 3 is a perspective of a special clamp t for supporting the assembly shown in Fig. 2; Fig. 4 is a partial section through a first form of device for heating the glass blocks;

Fig. 5' is a plan of the structure illustrated Fig. 6 illustrates asecond .form of heating device;

Fig.f drawing elements;

8 is a section taken on line 9-9 of Fig. .9 illustrates the tube cutting device in elevation;

Fig.l 10 is a section taken on line 11-11 of Fig. 9;- l i Fig. 11 shows aV simplified form of cutting device; I

Fig. .12 is a detail, in elevation, ofthe structures controlling the operationof the tube,- cutting device;

Fig. 13 represents, in plan, the structures shown in Fig. 12;

Fig. 14, is an elevation, partially in section, of the heating, drawing and cutting devices in assembled relation. I

Referring to Figs. ,1 to 5 of the drawings,

there is shown a solid block of glass 1` having a centralorice 11 therethrough and having 7 represents, `in elevation, the tube i a recess on the under face and a projection on the upper face thereof,-a mandrel 2, 3, 4 adapted to receive blocks 1 land formed of ferro-nickel or similar heat resisting material, portion 2 being of slightly less diameter than 11, while portions 3 and 4 are reduced to coact with proper suspending clamps, aheat-resisting tube 5 formed of a material similarto that of the mandreL-a sleeve 6 attached Ato rod 5 and permitting variation of the vertical position of a tapered fire-clay or' fire-brick die 7 having a circular, oval, triangular, square, polygonal or other desired transverse section,-an infusible disc 8 conforming in shape tothe base of block 7 but extending slightly beyond the periphery of the latter,-a pair of hingedly mounted suspending clamps 91, 92 adapted to fit into recesses 3 and 4 respectively and to be opened successively to permit blocks of glass to be strung onto mandrelv 2one of said clamps being maintained closed to assure suspension of the mandrel-die assembly,-a pivotally mounted lockingdevice 10 having pairs of oppositely directed arms formed at one end thereof adapted to embrace the arms of clamp 91 or 92 and assure the maintenance of one or the other of these clamps in locked position,- a series of blow torches 11 mounted on a common base,-a ring 12 supporting the torch assembly,-balls 13 interposed between the torch base and ring 12,-a llink 14,-a pin 15 eccentrically mounted on rotatable disc 152 and adjustable in position along a slot-151,- sleeves 16 and 17 limiting'the heating action of the torches, sleeve 16 being, preferably,

fixed, and sleeve 17, adjustable in osition.

It is to be noted that, since the unction of clamps 91 and 92 is to maintain the mandreldie assembly rigidly in a predetermined position, it may be desirable to add a third clamp similar to the twoalready described whereby two of the three clamps may be always maintained closed and a perfect alignment of the mandrel-die assembly so assured. It will be noted further that the 'rotation of disc 152 results in an oscillatory movement of torches 11, the position of pin 15 beingl adjusted so that the oscillatory movement of the torchbase corresponds to the distance between any pair-of adjacent torches i. e. for a heating assembly containing 10 torches, the distance which the supporting base moves at each oscillation should correspond to 116 of the circumference. Even heating of the entire periphery of the glass-blocks is thus assured. Sleeves 16 and 17 delimit 4 heating zones. In zone A, the glass blocks are maintained at the temperature to which they have been preheated by .the gases rising from the lower more highly heated zones. Zone B is s ufficiently hot to assure the joining of the superposed glass-blocks, and in zone C, the latter become plastic and flow down and over die 7 8 into the protection offered by sleeve 17 in zone D.-

The proper choice of materials for the die assembly 7, 8 is one of the essential elements in the production of perfect tubing. Cone 7 is best formed of -a thin, line-grained refractory clay, baked at a high temperature and glazed'externally.` The glazing facilitates the movement of the viscous glass mass over the cone and -prevents bubbles of gas from being driven from the latter into the former. Plate 8 should be formed of a metal which neither oXidizes (like iron) nor colors the glass with which it is in contact (like copper). Pure nickel has been found to give the best results. Plate 8 may be mounted as shown in Fig. 2 or may be supported between a pair o'f stiffening rings 81, 82 formed of ferro-nickel, nichrome or the like (Fig. 22). Plates thus constructed present va smooth, unalterable, surface of contact for the glass tube being drawn and yield a product having a brilliant internal surface. It is to be understood,y of course, that a nickel plated. or covered die may be used instead of a solid block of this metal. y

Inasmuch as it is intended to give a complete unified description further on of the mode of operation of each of the various units constituting a complete tube-drawing machine in the order in which they function, it suffices merely to remark here, that the purpose of the structures so far described is merely to convert a solid block of glass into a plastic mass and to pass the latter over a die to 10o produce a tube having the sectional form desired. This is accomplished during the passage of blocks 1 through heating zones A, B,

C and D in internal contact with die 7, 8.

The form of heating device shown in Fig. 6 105 differs from the one already described only in' the-substitution of a furnace -18 heated by electricity, coal, gas, oil or otherwise for the blow-torchesI shown in Figs. 4 and 5. The mode of operation remains the same. Here, 110 sleeve 16 is suspended from the tap of the furnace, while sleeve 17 is supported on an annular member 171 which may be moved upward or downward by turning wing-nuts 173 on threaded-bolts 172. A pump 70 has 115 been represented in this figure attached to one end of tube 5 and servesto exhaust or to pumpair or a gas into or out of the interior portion of the tube being drawn. This pump may also be used in the form of device shown 120 in Figs 2 to 4 and in a manner to be set forth in another part of the specification.

Referring now to Figs. 7 and 8, there is shown an apparatus for drawing the glass tubes `formed by passage over die 7, 8 and com- 125 prising, a series of rotatable shafts 19 mounted vertically in line with one another and supported by an upright 251,-a series of wheels 21 of the same diameter mounted on shafts 19 (three have been shown by way of example) 130 t each having a fiat-bottomed, asbestosslined groove 211 formed therein,a sprocket-wheel 22 rigidly connected to the highest of said 21,--a seties of pins 26,-4-a series of bent arms 27 pivotally suspended from pins 26,-a series of wheels 28 of substantially the same di'ameteras ,wheels 21'and each having an asbestos lined angular groove 281 adapted to properlycontact with the tube to be drawn,- and a series of weights 29y adjustably mounted on the horizontal portion of bent-'arms 27.`

From the foregoing it will be evident that the tube descending from die 7 I 8 will be seized between pairs' of wheels 21, 28 (Fig. 13) and will be drawn regularly under the action of a single drivee'gear 24 in the direction of the axis X Y of the machine. The distance between wheels 21 and 28 may be changed by shifting their supporting up-l rights 251, 252, along frame-work 20, 20 and relooking' the uprights in position by means of set-screws or the like. Wheel 21 is made flatbottomed so that the linear velocity of the tubing being drawn should not vary when the diameter of the latter is changed. If the groove in wheel 21 were angular (like that of wheel 28) instead of fiat bottomed, the linear velocity of a tube of large diameter `would be greater for a given angular velocity of wheel 21 since the points o'f contact of the tube and wheel would be further from the center of the latter. Wheel 28 may be pro- 'vidcd wi an angular groove sincea better grip on t e tube is obtained, the angular form having no eiiect on the linear velocity of the tube because of the passive rle (mere pres- To obtain the finished tube, it .remains only to section at desired intervals. `This is accomplished automatically by the speciala-p- Aparatus shown in Figs. 9, 10, 12 and 13 comprisinvr a pair of rotating lknives 3() adaptedl to sectlon a glass tube, a frame 31 supporting the knife controldevicesf--guide ways 32 for the movement of `trame 31,-a counterbalancing system 33, 34,--a pulley 35 and iiy- .wheel 36 rotatably supported on frame 20 above the tube drawing assembly and driven from a motor (not shown) by belt 37,-a pinion 38 driven by pulley 35 and driving a gear 39 mounted on a shaft 40p-a pinion 41 keyed to shaft 40 and having-teeth formed on only a portion ot theperiphery thereof whereby either one of two gears 42 and 43 positioned to come into mesh with the teeth of said pinion may be driven thereby,-three` large teeth or cams 411, 421, 431 rigidly mounted on pinions 41, 42 and 43 respectively and positioned so that at the instant that partially toothed gear moves out of mesh with `either pinion 42 or 43, large tooth" or cam 411 engages with tooth 421 or 431 as the case may j a pair of'bent leversi49 pivotally mounte on shafts '50, each carrying a pair of pulleys 51, 511, cables 52 driving pulleys 51 from a double pulley 53, cables 54 extending from pulleys 511 toa pair of pulleys 55 mounted in driving relation to knives 30, a shaft '56 carrying double-pulley, 53, a pulley 57 driving shaft 56 and driven from a motor (not shown), a connecting rod 61 pivotally connected at 492, 492 to arms 491-, 4910i levers 49 and tending y'to be maintained towards the right by spring l` (position where knives 30, 30 are separated), a species of inclined 'cam 58 rigidly (or, if desired, adj ust-ably) mounted on frame 20v` a linger 59 positioned so as to contact'with the left hand surface of cam v58 duringthe descentv of Vframe 31 and limited in its pivotal towards `the left by shoulder 592, a spring 591 tending to maintain tingerV 59 in Contact, with shoulder 592 but permitting said finger to bend towards theright when it rides over the.

right hand surface of -cam 58 during the ascending movement of frame 31,4-and an assembly for gripping the tube, at the m0- Iment that knives 30, 30`section the latter, consisting of a lixed jaw 71` adjustable in position by means of a threaded rod 72 and having its glass contacting surfaces lined with asbestos, and a movable jaw or lever 73 tending to move towardsy its open position under the action of spring 7 5 and towards its closedposition under the spring 74. 1 f

Shaft 40 mayl be arranged to drive the tube-drawing unit `by mountinga sprocket 48 in driven relation thereto andy passing chain 23' over said sprocket.

j, The manner in which the various units of the complete machine operate is as follows A number of lass blocks 1 which have just been made by owing, pressing, or casting and which are still hot, or which havebeen reheated in .any convenient form of furnace, are mounted on mandrel-die assembly2, 7, v8. This is accomplished by opening clamp 91, lowering a block between clamps 91 and 92, closing clamp 91 and opening clamp 92 and pull exerted by arm 491 on a continuing until a column of blocks of proper ous operating-elements may be designed soA under the cooling action of the air. If desired, jets of air may be directed againstthe extruded or drawn tube to increase thevcooling and hardening'eifct. The first tubin platform (Fig. 14) and rejected (since it is generally imperfect) and the extremity of the tube thus obtained is introduced between drawing wheels 21 and 28fwhich draw the tube out and,-since the speed of wheels 21" may be regulated by manipulating a rheostat or other convenient form of speed regulating device (not shown)v attached to the motor in driving-relation to said wheels,produce tubing of any desired diameter (or sectional measurement) the pressure exerted by wheels 28being adjusted by. moving weights 29. The tube then enters the tube-sectioning unit and descends between cutters 30, 30, rotating in opposite directions, which descend at the same speed as the tube. W hen frame 31 arrives at the point in its downward course where finger 59 engages with the left hand surface of cam 58,1eft-hand arm 491 will exert a pull on right-hand arm 491 through the intermediary of link 61 and cause knives 30, 30 to lapproach one another. [At the same time movable aw 73 will be drawn by spring 74 towards its gripping position. \The ,varithat jaw 73 grips the tube just prior to its being sectioned by knives 30, 30. During the downward movement of frame 31,partially toothed gear 41 is in mesh with one of the al pinions 42, 43, and the other of these two pinions is being rotated (while out of contact with gear 41)Jpassively, and in the opposite direction as its mate, by rack and pinion assembly 45, 46, 47. Immediately after the tube is sectionedathe smallteeth of gear 41 move out of mesh with the small teeth of the pinion with which they have been in contact f serve merely to assure smooth engagement bet tween the small teeth on gear 41 and those on pinions 42 and 43. The upward movement then begins. During the upward movement, finger 59 contacts with the right hand side of cam 58, is bent towards the right (Fig. 10), and snaps over the latter back into vertical position under 'the action of spring 591, spring 60 maintaining knives 30, 30 `in separated position. When frame 31 reaches the top of its course, tooth 411 meshes with either 421 extruded is sectioned at the level of the secon oi' 431 and said frame descends in the manner described in connection with the reversal of the descending movement. Itis to be understood, of course, that the toothed andsmooth portions of gear'41 should be spaced to assure proper timing of the reversing movements `and that the various gears should be chosen so that cutters 30, 30 move downward at theY fuse together and produce tubing, the ru`p ture, if any, occurring after cooling and extending over only va short length.

If, in the course of the drawing operation, it be-desired-to vary the diameter of the tube, it suiiices only to change the velocity oi wheels 21, 28 and increase or decrease the amount of heat being furnished to blocks I11 by the blow-torches lor other source of eat.

When die 7 8 is elliptical or oval the tube formed thereby is of a corresponding shape and by exerting suction or pressure on the inside of the tube (pum 70, Fig. 6) the fiatness of the latter may be diminished or increased during the 'drawing operation.

In the special form of cutting device repin Fig. 10 are replaced by a pair of metal iexible arcs 63 which section-the heated tube by their local chilling action. Here linger 59 actuates a lever 66, pivoted at 65, to operate a pair of links 62, 67 so as to oscillate a pair of arms 621, I68 against the resistance offered by spring 60 land bring arcs 63, 63 supported by flexible elements 631, 631 into contact with the tube. The timing of the oscillatory movement of elements 63, 63 is effected by cam 58 .in precisely the same way -as described in connection with the cutting device shown in Fig. 10.

The various types of apparatus lend themselves readily to producing tubing with a distinctive colored stripe or mark, it being necessary to merely interpose a ring, a ball or a rod of colored glass between adjacent blocks 1 or to insert the former in any way desired into a recess formed in the latter in the manner represented by rod 12 in Fig. l.

From the foregoing, it will be seen that vthe hereinabove described method and apparatus permits non-glassmaking countries to import conveniently transportable glassblocks and manufacture as desired tubing of any desired size, section, composition or color. Glass manufacturers are provided, for the first time, with means for running their vae lresented in Figfll, the knives represented Finally, a single apparatus is provided per-l mitting the continuous production of tubtion during the drawing operation.

ing'of varying diameter, color and composi- The inventor is aware of the existence of devices in which a tube is formed by flowing molten glass onto an inclined rotating mandrel through which air is being blown. His device replaces` the rotating, by a stationary, forming element and eliminates the necessity of introducing air into lthe center of.

the tube, the latter operation being purely optional.` It is to be noted further that since the tube is drawn vertically an upward Idraft is produced through the bore thereof tending to effect a blowing action.

In the following claims, the word fixed forming element is employed as meaning non-rotating as distinguished fromthe ro-l tatin elements used heretofore.

1. .gfhe method t of 'forming continuous vitreous tubing which comprises heating a hollow solid vitreous mass in internal contact -with a fixed forming element, and drawing the tube thus formed over said element.

2. The method of forming vitreous tubing of diverse sectional area which comprises the Steps of forming a block of solid material, heating said block until it flows, and drawing the viscous Vmass yend-wise over the entire periphery of a fixed forming-element at a rate varying in accordance with the sectional areaV desiredand varying the amount of heat supplied to said block in accordance with the rate at which the drawing operation is being .ef-..- fected.

est at a point adjacent that portion ofthe mandrel `having the largest section.

6. The method of forming vitreous tubing whiehcomprises the steps of mounting a hollow solid vitreous block on a mandrel having a portionof its surface formed of metal, heating said block until plastic, and drawing the plastic mass endwise over the mandrel in contact with said metallic mandrel portion.

7 The method of forming marked vitreous tubing which comprises heating a solid block composed `of vitreous material of dierent compositions in internal contact with a fixed forming element, and drawing the tube thus formed over said element.

8. In a tube drawing device having a suspended elongated forming 'mandrel with means for supporting said mandrel comprising separate clamps mounted in spaced relation adjacentone extremity of said mandrel.

In testimony thereof I have signed this specification.

PIERRE ANDR FAVRE.

was formerly the block while the latter is plastic.

4. The method of forming vitreous tubing comprising'the steps of forming a block of solid material having an orifice therethrough of relatively small sectional area, heating said block to plasticity, and drawingit endwise, While plastic, over a fixed forming element of greater sectionalarea than. that of the orifice formed therein whereby a tube having an orifice of relatively large sectional area isv produced.

5. The method of forming vitreous tubing which comprises the steps of mounting a hollow, solid, vitreous mass on a mandrel having a portion thereof of progressively increasing section, and heating said solid vitreous mass so that its temperature is high- 

